oil pressure acting up and need new cats!!!!

Nando559

Registered User
So today while I was driving my 90 thunderbird sc automatic into the garage I noticed the stock oil pressure gauge moved back and fourth. It ONLY did it when I would shift gears like reverse to neutral or from park to drive! Anyone know what could be wrong????:confused:

Also my car did NOT pass the stupid California SMOG! It is the "NO" test, from what Ive read on cars that dont pass this test is that most likely my catalytic converters! My test reading was....1502 at 15mph, MAX. that it can be is 530:( and 1237 at 25mph, MAX accepted is 487:mad: Does anyone know what part/parts I NEED to check or buy?? Cali. approved CATs cost WAY MORE than normal ones! $400 for both installed is the best quote ive gotten so far!!:eek:
 
the stock oil pressure gauge is pretty much a dummy switch. they are prone to get stuck, or not move to their full potential. pull your dash out and try cleaning the 2/3 prongs for the oil gauge, if that doesn't help, replace your oil pressure switch. it's located between the p/s and water pump on the d/s of the motor. it takes a 12 point 15/16 socket.
 
The high NOx is more likely a vacuum leak than an actual bad converter. I would test the vacuum system to the Nth degree before spending money on the exhaust.
 
the stock oil pressure gauge is pretty much a dummy switch. they are prone to get stuck, or not move to their full potential. pull your dash out and try cleaning the 2/3 prongs for the oil gauge, if that doesn't help, replace your oil pressure switch. it's located between the p/s and water pump on the d/s of the motor. it takes a 12 point 15/16 socket.

I will do this and post back on what happens! HOPE this fix that problem....THANKs for the help!:cool:

-Fernando
 
The high NOx is more likely a vacuum leak than an actual bad converter. I would test the vacuum system to the Nth degree before spending money on the exhaust.

How do I check for leaks or do I take it to get checked at a shop??:confused:
 
How do I check for leaks or do I take it to get checked at a shop??:confused:

Well, what's the vacuum gauge reading at idle? That's a starting point.

Also, you can use an unlit propane torch, holding the gas near all of the intake joints, along the sides of the intake manifold, etc. See if the engine revs up at any point.

The best way to test it is with a smoke machine, but you will have to find a shop that has one.
 
Well, what's the vacuum gauge reading at idle? That's a starting point.

Also, you can use an unlit propane torch, holding the gas near all of the intake joints, along the sides of the intake manifold, etc. See if the engine revs up at any point.

The best way to test it is with a smoke machine, but you will have to find a shop that has one.

Ill let you know what it reads as soon as I get home!

If it revs up is that good or bad? Sorry if I sound stupid for asking that but im new to learning about Vac leaks

-Fernando
 
Ill let you know what it reads as soon as I get home!

If it revs up is that good or bad? Sorry if I sound stupid for asking that but im new to learning about Vac leaks

-Fernando

Revs up is bad, because it shows that the combustible gas is getting sucked in through a gap.
 
currently working onthe car....

Well, what's the vacuum gauge reading at idle? That's a starting point.

Also, you can use an unlit propane torch, holding the gas near all of the intake joints, along the sides of the intake manifold, etc. See if the engine revs up at any point.

The best way to test it is with a smoke machine, but you will have to find a shop that has one.

At idle its reading 20 but I shift it in reverse or drive and it moves to about 17. Then when I put it back into park it stays at 19:confused:
 
At idle its reading 20 but I shift it in reverse or drive and it moves to about 17. Then when I put it back into park it stays at 19:confused:

See, that sounds pretty good. Maybe it's not a vacuum leak.

I guess the mixture could still be lean from bad O2s or something.

Over-advanced timing could result in high NOx. You could put a timing light on it and see what base timing is - it should be 10degrees BTDC. (You can lock the timing at base by pulling the SPOUT plug near the ignition module.
 
See, that sounds pretty good. Maybe it's not a vacuum leak.

I guess the mixture could still be lean from bad O2s or something.

Over-advanced timing could result in high NOx. You could put a timing light on it and see what base timing is - it should be 10degrees BTDC. (You can lock the timing at base by pulling the SPOUT plug near the ignition module.

Can I have bad O2 sensors and not have a check engine light on?

I can adjust the timing even if the car has the auto adjusted timing?
 
I will need an emission test on my bird come August for the first time since I modified it. I hope I don't run into any issues.

So, I started investigating emissions and this is what I found for NOX

Nitrogen oxides (NOx) - Generated when nitrogen in the air reacts with oxygen at the high temperature and pressure inside the engine. NOx is a precursor to smog and acid rain. NOx is a mixture of NO and NO2. NO2 destroys resistance to respiratory infection. For dogs most of the nitrogen dioxide is removed in the nasal cavity. Jumbo vehicles and delivery trucks blow hot exhaust, containing life dangerous quantities of NO2 into the atmosphere.


Looks like it could be a few things

EGR
CAT
KNOCK SENSOR
IGNITION TIMING


I read an article on the net that stated a guy who tried everything and kept failing. Finally he broke down and changed the cats; he then passed with flying colors. I also read that you want to make sure your computer re-learns on several cold\warm cycles before testing.

Good luck, hope it passes.
 
Can I have bad O2 sensors and not have a check engine light on?

I can adjust the timing even if the car has the auto adjusted timing?

It's possible ... but perhaps not likely.

For the timing, I am not suggesting that you adjust it. That should only be done through tuning the computer. But I am saying it would be good to make sure it is at 10 degrees. (If the harmonic damper goes bad, the timing sensor ring can slip relative to the crank, and throw off the timing.)

There is a notch on the rear edge of the crank pulley. If you hook up the timing light to the #1 cylinder (front passenger side) and let it flash, you can compare the mark on the crank pulley to the numbers on the plastic damper cover.

If there aren't any drivability issues with the car, then maybe it is just time for cats. However, I am just naming these things because I would rather see you try the cheap fixes first. The worst thing would be replacing the cats, then still failing, and still having to find out what's wrong.

Also, if there is an ongoing problem, it may wear the new cats out quickly ... so it's good to just check things out before laying out the cash.

Edit:
I forgot to ask, how did the other numbers (HC & CO) look? Were they very clean, or did they just squeak by?
 
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Well after working on the car MOST of the day and part of the night.... the car now wont start!:mad:
I took apart the supercharger top, IC tubes, IC, and the fuse box with all the wiring(replaced the battery holding tray). Put it all back together and resealed the IC with tubes(used Copper High temp RTV). When I went to turn the car on everything seem normal until I turned the key..Car turns on but shakes and turns off right away(RPMs go up then down). If I step on the gas it stays on but revs up and dwn til I let go of the pedal! Any ideas??:confused:
 
Oil pressure readings jumping around is most likely caused by a loose connection at the sender. This can be fixed by crimping the connector with pliers for a tighter fit and reinstalling. Here is a picture of the sender and the single wire connection (red) that just pushes onto the sender.

http://www.sccoa.com/forums/attachment.php?attachmentid=32521&d=1210723267

David

Thanks! The problem is fixed now.:D BTW I couldn't look at the link because im not a member(Ive been waiting for a year already to be a member!:eek:)
 
I will need an emission test on my bird come August for the first time since I modified it. I hope I don't run into any issues.

So, I started investigating emissions and this is what I found for NOX

Nitrogen oxides (NOx) - Generated when nitrogen in the air reacts with oxygen at the high temperature and pressure inside the engine. NOx is a precursor to smog and acid rain. NOx is a mixture of NO and NO2. NO2 destroys resistance to respiratory infection. For dogs most of the nitrogen dioxide is removed in the nasal cavity. Jumbo vehicles and delivery trucks blow hot exhaust, containing life dangerous quantities of NO2 into the atmosphere.


Looks like it could be a few things

EGR
CAT
KNOCK SENSOR
IGNITION TIMING


I read an article on the net that stated a guy who tried everything and kept failing. Finally he broke down and changed the cats; he then passed with flying colors. I also read that you want to make sure your computer re-learns on several cold\warm cycles before testing.

Good luck, hope it passes.

THANKS! Ill look into these things after I get my car running again.
 
It's possible ... but perhaps not likely.

For the timing, I am not suggesting that you adjust it. That should only be done through tuning the computer. But I am saying it would be good to make sure it is at 10 degrees. (If the harmonic damper goes bad, the timing sensor ring can slip relative to the crank, and throw off the timing.)

There is a notch on the rear edge of the crank pulley. If you hook up the timing light to the #1 cylinder (front passenger side) and let it flash, you can compare the mark on the crank pulley to the numbers on the plastic damper cover.

If there aren't any drivability issues with the car, then maybe it is just time for cats. However, I am just naming these things because I would rather see you try the cheap fixes first. The worst thing would be replacing the cats, then still failing, and still having to find out what's wrong.

Also, if there is an ongoing problem, it may wear the new cats out quickly ... so it's good to just check things out before laying out the cash.

Edit:
I forgot to ask, how did the other numbers (HC & CO) look? Were they very clean, or did they just squeak by?


Just asking because I have no lights on my dash except the ABS light.

Oh, ok. Thank you for explaining it to me because I got confused a little bit.

My HC was 32 at 15mph and 25mph..MAX allowed at 15mph is 73 and at 25mph its 56

The CO was 0.24 at 15mph..MAX allowed is 0.49 and 0.21 at 25mph..max allowed is 0.39
 
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The HC and CO numbers look all right. So the mixture is probably okay, I guess.

For the shaking engine ... I would suggest that you check the spark plug wire routing first. Cylinders 5 and 6 are supposed to be installed in the reverse of where you would expect them to go.
 
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